Process of making acetyl-cellulose plastic compounds.



i To all whom it may concern facture of lacquers,

UNITED STATES PATENT OFFICE.

WILLIAM G. LINDSAY, OF CALDWELL, NEW JERSEY, ASSIGNOR TO THE CELLULOIDCOMPANY, OF NEW YORK, N, Y., A CORPORATION OE NEW JERSEY.

PROCESS OF MAKING ACETYL-CELLULOSE PLASTIC COMPOUNDS.

Specification of Be it known that L'WILLIAM G. LINDSAY, a citizen of theUnited States, residing at Caldwell, in the county of'Essex and State ofNew Jersey, have invented certain new and useful Improvements inProcesses of Making Acetyl-Cellulose Plastic Compounds, of which thefollowing is a specification.

The various compositions to which the present invention relates areemployed in the arts, sometimes as imitations of natural substances andsometimes as films which are 'used for photographic purposes. Althoughthe final or useful form of the different compounds of acetyl celluloseis that of a solid or dry material, the different processes ofconversion into this final solid form involve, as is well understood,the employment of solutions or mixtures of varying consistencies as toelasticity, stiffness or fluidity, depending generally upon theproportion or kind of solvent used to the amount of the originalbaseacetyl cellulose.

In the treatment of acetyl cellulose for the production of solutions forthe manuvarnishes, photographic films, and flexible or plasticcompounds, have discovered that a mixture of ethyl acetate and methylalcohol constitutes a solvent of that variety of acetyl cellulose whichis freely soluble in acetone.

It is well known that ethyl acetate or acetic ether has been proposed asa solvent for the acetone-soluble variety ofv acetyl cellulose and thatthe ethyl acetate found on the market contains varying amounts of ethylalcohol. I have discovered, however, that when the commercial or the100% ethyl acetate is diluted with methyl alcohol in. certainproportions, the mixture exerts an increased solvent action on theacetyl cellulose of the variety described 'for the preparation of acetylcellulose plastics.

The best proportions I have found are 30% to 40% of methyl alcohol mixedwith 60% to 70% of ethyl acetate, and one example of practising myinvention is as follows: To .100 parts, by weight, of theacetone-soluble variety of acetyl cellulose, I

add 10 to 20 parts, by weight, of para'ethyl- Letters Patent.

2, Serial No. 699,235. Divided and this applicatio Serial No. 32,862.

stirring and add to the mixture thus obtained from 60 to 7 0 parts, byweight, of a mixture composed of 70 parts, by volume, of ethyl acetateand 30 parts, by volume, of methyl alcohol. The mass is then thoroughlyincorporated by suitable malaxating or, kneading and when a uniformmixture is obtained the excess of solvent is allowed to evaporate andthe dough-like product thus obtained is further worked up according tothe methodwhich is well known in the manufacture ofnitro-cellulose-camphor compounds.

Having thus described my invention, what I claim is:

1. The process of making acetyl cellulose plastic compounds from thatvariety of acetyl cellulose which is freely soluble in acetone whichconsists in mixing paraethyltoluolsulfonamid with the acetyl cellulose;adding a mixture of ethyl acetate and methyl alcohol; allowing theexcess of solvent to evaporate; working the mass on rolls or in presseswith the application of heat, substantially as set forth.

2. The process of making acetyl cellulose plastic compounds from thatvariety of acetyl cellulose which is freely soluble in acetone thatconsists in mixing paraethyltoluolsulfonamid with triphenyl-phosphateand acetyl cellulose; adding a mixture of ethyl acetate and methylalcohol; allowing the excess of solvent to evaporate; working the masson rolls or in presses with the application of heat, substantially asset forth.

3. The process of making acetyl cellulose plastic compounds whichconsists in treat ing that variety of acetyl cellulose which is freelysoluble in acetone with ethyl'acetate in admixture with methyl alcoholsubstan- Patented Nov. 7, 1916.

tially in the proportions described and with paraethyltoluolsulfonamid;and manipulating the mass.

I 4. The process of making acetyl cellulose plastic compounds whichconsists in treating that variety of acetyl cellulose which is freelysoluble in acetone with ethyl acetate in admixture with methyl alcoholsubstantially in the proportions described and withparaethyltoluolsulfonamid and triphenylphosphate and manipulating themass.

In testimony whereof I aflix my signature. WILLIAM G. LINDSAY.

